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Multi-axis bubble vial deviceRelated Patent Categories: Geometrical Instruments, Indicator Of Direction Of Force Traversing Natural Media, Level Or Plumb, Terrestrial Gravitation Responsive, Electrically Actuated Signal Or Indicator, Fluent Sensor, Having Light Or Radiant Energy Detecting Circuit Control ElementMulti-axis bubble vial device description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070169362, Multi-axis bubble vial device. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] Not applicable. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not applicable. BACKGROUND OF THE INVENTION [0003] Level vials of various types are used in a wide variety of control systems in which the orientation of a machine element is measured and controlled. Typically, the vial is secured to the machine element. The vial moves with the element and provides an electrical output or outputs that indicate the orientation of the level vial and the machine element with respect to at least one axis. Such level vials may, for example, form a part of a system that controls the orientation of a laser beam transmitter and the orientation of the beam produced by the transmitter. Preferably two level vials are included in a transmitter of this type, with each vial providing an indication of orientation of the transmitter with respect to one of a pair of substantially orthogonal axes. [0004] Typically a level vial includes a glass or plastic vial casing that defines an elongated fluid chamber. The chamber has a curved upper surface which slopes downward, away from the center of the vial. The chamber is partially filled with fluid so that an air bubble is trapped in the chamber with the fluid. As the level vial is tilted about a generally horizontal axis, normal to the direction of elongation of the chamber, the bubble in the vial moves across the curved surface of the chamber toward the more elevated of the two ends. The degree of movement of the bubble is an indication of the orientation of the vial with respect to the horizontal. Various arrangements have been used to detect the position of the bubble and to produce an electrical signal that is dependent upon the orientation of the level vial and therefore indicates the orientation of the machine element. [0005] One type of level vial comprises an electrically nonconductive vial casing, usually made of glass, that defines an elongated, arcuate chamber which curves generally downward toward its opposite ends. A quantity of electrically conductive fluid is provided in the chamber. Such a fluid may, for example, have a ketone component. A pair of end electrodes electrically communicate with the upper portions of the chamber adjacent its opposite ends and extend toward the central portion of said chamber. [0006] A common electrode extends substantially the entire length of the chamber along its lower surface. The air bubble in the chamber rises to whatever portion of the chamber is uppermost. It will be appreciated that, as the vial is tilted in one direction, the electrical impedance of a path from one end electrode through the electrically conductive fluid to the common electrode will increase, while the electrical impedance of a path from the other end electrode to the common electrode will decrease. When the vial is tilted in the opposite direction, the end-electrode-to-common-electrode impedances change in the opposite fashion. While this level vial arrangement functions well, it requires that lead connections be provided both above and below the level vial. This, in turn, means that all associated components cannot be mounted on a single circuit board. Additionally, two such level vials are required to assess the orientation of a machine element about two horizontal axes. [0007] Other level vials use a photo-optical arrangement for detecting the position of the bubble in the fluid chamber. In one such arrangement, a light source emits a beam of light which passes through the chamber and is detected by a pair of photodetectors adjacent opposite ends of the vial. As the bubble moves toward one of the ends of the vial, the amount of light reaching the photodetectors is changed, and the relative electrical output signals from the photodetectors provide an indication of the degree of tilt of the vial. This level vial arrangement has the disadvantage of requiring components above and below the vial in order to determine the position of the beam. The disadvantage of this arrangement is that it requires that a light source and photo-detectors, and their associated electrical connections, be provided both above and below the level vial. As with the other type of level vial discussed above, this means that all associated components cannot be mounted on a single circuit board. Additionally, two such level vials are required to assess the orientation of a machine element about two horizontal axes. [0008] It is seen that there is a need, therefore, for a level vial construction in which all of the electrical components can be mounted on a single circuit board, and for such a level vial construction in which inclination with respect to two substantially orthogonal axes may be measured with a single level vial. SUMMARY OF THE INVENTION [0009] A multi-axis bubble vial device, constructed according to the present invention, meets these needs. The device includes a bubble vial having a transparent vial body defining a fluid chamber with a curved upper surface, and a quantity of fluid partially filling the chamber. The fluid defines a bubble in the upper portion of the chamber which moves along the upper surface in dependence upon the orientation of the vial. A centrally positioned light source, above the bubble vial, directs light into the chamber. Four light sensors are positioned above the bubble vial and arranged circumferentially around the centrally positioned light source. A first pair of the sensors is positioned on opposite sides of the light source along a first axis. A second pair of light sensors is positioned on opposite sides of the light source along a second axis. The second axis is substantially perpendicular to the first axis. A reflector is positioned beneath the fluid chamber, such that light emitted from the light source passes through the bubble and the fluid, and is reflected by the reflector back to the light sensors. The relative levels of light detected by the first pair of sensors indicate the orientation of the first axis with respect to horizontal, and the relative levels of light detected by the second pair of sensors indicate the orientation of the second axis with respect to horizontal. [0010] The reflector comprises a mirrored reflector positioned beneath the bubble vial. The reflector may comprise a mirror having a reflective surface, the mirror being adhesively secured to the bubble vial by an adhesive having a refractive index which is substantially the same as the refractive index of the material from which the bubble vial is made. [0011] The reflector may comprise a reflective coating in the fluid chamber on the surface of the chamber opposite to the curved surface. The surface opposite the curved surface is preferably substantially flat. [0012] The centrally positioned light source comprises a light emitting diode. Each of the four light sensors comprises a photodiode. [0013] The sides of the fluid chamber between the curved upper surface and the opposite surface are preferably light absorbing, whereby extraneous light reflections are reduced. The bubble vial may be shielded from extraneous light that might otherwise introduce error into the measurement of the orientations of the device along the first and second axes. The reflector may comprise a reflective coating on the outside, bottom surface of the bubble vial. [0014] A multi-axis orientation determination device according to the present invention uses such a multi-axis bubble vial device. The multi-axis orientation determination device includes a bubble vial having a transparent vial body defining a fluid chamber with a curved upper surface, and a quantity of fluid partially filling the chamber to define a bubble in the upper portion of the chamber. The bubble moves along the upper surface in dependence upon the orientation of the vial. A centrally positioned light source is mounted above the bubble vial, directing light into the chamber, and light sensors are positioned above the bubble vial and arranged circumferentially around the centrally positioned light source. A first pair of the sensors is positioned on opposite sides of the light source along a first axis, and a second pair of the sensors is positioned on opposite sides of the light source along a second axis. The second axis is substantially perpendicular with respect to the first axis. Each of the sensors provides an electrical output signal in dependence upon received light. A reflector is positioned beneath the fluid chamber such that light emitted from the light source passes through the bubble and the fluid and is reflected by the reflector to the light sensors. A first circuit, responsive to the electrical output signals from the first pair of sensors, provides an indication of the orientation of the bubble vial in the direction of the first axis from the relative levels of light detected by the first pair of sensors. A second circuit, responsive to the electrical output signals from the second pair of sensors, provides an indication of the orientation of the bubble vial in the direction of the second axis from the relative levels of light detected by the second pair of sensors. [0015] It is an object of the present invention, therefore, to provide a multi-axis bubble vial device, and a multi-axis orientation determination device including such a bubble vial device, in which the orientation of the bubble vial device may be determined with a single device, and in which the electrical connectors are all positioned on a single side of the device for connection to a printed circuit board. Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings, and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS [0016] FIG. 1 is a perspective view of a multi-axis bubble vial device according to the present invention; [0017] FIG. 2 is a plan view of the multi-axis bubble vial device of FIG. 1; [0018] FIG. 3A is a sectional view of the multi-axis bubble vial device taken generally along line 3-3 in FIG. 2; [0019] FIG. 3B is a sectional view, similar to that of FIG. 3A, illustrating an alternative construction of the multi-axis bubble vial device according to the present invention; Continue reading about Multi-axis bubble vial device... Full patent description for Multi-axis bubble vial device Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Multi-axis bubble vial device patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Multi-axis bubble vial device or other areas of interest. ### Previous Patent Application: Tilt sensor and method of providing the same Next Patent Application: Posture and body movement measuring system Industry Class: Geometrical instruments ### FreshPatents.com Support Thank you for viewing the Multi-axis bubble vial device patent info. IP-related news and info Results in 0.73829 seconds Other interesting Feshpatents.com categories: Medical: Surgery , Surgery(2) , Surgery(3) , Drug , Drug(2) , Prosthesis , Dentistry 174 |
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